1. Field of the Invention
The subject invention generally relates to an exhaust manifold gasket for use in an automotive exhaust system. More specifically, the subject invention relates to an exhaust manifold gasket that is adaptable for installation on a variety of engines.
2. Description of the Related Art
It is known that automotive exhaust systems interface with an engine to convey exhaust gas away from cylinders in the engine. More specifically, an exhaust manifold is mounted to a cylinder head of the engine, and receives the exhaust gas as the exhaust gas exits the cylinder head.
Exhaust manifold gaskets are known in the art. Exhaust manifold gaskets seal the exhaust manifold to the cylinder head. The exhaust manifold gaskets prevent the exhaust gas from escaping, which could create noise, cause heat damage to components in the engine compartment, and/or create environmental issues. The exhaust manifold gaskets, which are also characterized as hot static seals due to the high temperatures that the exhaust manifold gaskets are required to withstand (up to 600° C. and higher), are often made of one or more layers of steel. Some auto manufacturers impose additional specification requirements. For example, some manufactures require that an anti-friction coating, which is also heat resistant, be applied on a side of the exhaust manifold gasket that is in contact with the exhaust manifold. The anti-friction coating enables slight movement of the exhaust manifold with respect to the engine to optimize the seal between the exhaust manifold and the cylinder head.
For engines having a V-shaped structure, two cylinder heads are arranged on opposite sides of the engine, due to the location of the cylinders. Thus, the exhaust system is required to have two separate exhaust manifolds on opposite sides of the engine, which requires two respective exhaust manifold gaskets. Fasteners are configured for the exhaust manifolds on the opposite sides of the engine to be generally mirror images of each other, which presents a number of problems for manufacturers of components for the exhaust system, in particular the exhaust manifold gaskets. For example, as described in further detail below, the exhaust manifold gasket must be flipped to be installed on the opposite sides of the engine, i.e., a different surface of the gasket faces the exhaust manifold on the opposite sides of the engine. As a result, both sides of the exhaust manifold gasket must be coated with the anti-friction coating.
Exhaust manifold gaskets are generally configured to have a series of mounting holes, each for receiving a fastener on the engine. Referring to FIG. 1, a conventional exhaust manifold gasket is disclosed. With this prior art exhaust manifold gasket, the mounting holes are diagonally spaced on each side of the exhaust manifold gasket and match a configuration of fasteners on the engine. More specifically, the exhaust manifold gasket defines multiple openings. The openings are defined along an axis A. One mounting hole is defined on each side of each opening. The mounting holes for each opening are arranged diagonally across the opening such that an axis B between the mounting holes intersects the axis A between the openings at a non-perpendicular angle. Because no complementary set of holes exist, the exhaust manifold gasket must be flipped during installation to fit the opposite side of the engine.
However, for the exhaust manifold gasket described above, one surface of the exhaust manifold gasket faces the exhaust manifold on one side of the V-shaped engine, and an opposite surface of the exhaust manifold gasket faces the exhaust manifold on the other side of the engine. As such, the entire exhaust manifold gasket must be coated with the anti-friction coating, even though the coating is only required for the surface that is in contact with the exhaust manifold. Anti-friction coatings are relatively costly. Therefore, coating both sides of the exhaust manifold gasket is more expensive than coating only one side of the exhaust manifold gasket.
Thus, there is an opportunity to overcome the deficiencies of the related art and lower the cost of the exhaust manifold gasket.